Apparatus for determining liquid levels



April 1939. w. P. THOMAS ET AL 2,153,213

APPARATUS FOR DETERMINING LIQUID LEVELS Filed July 31, 1955 2 Sheets- Sheet 1 l I I 11 INVENTORS WILL P. THomns CuRT): I. H ow 5E HFIRRY E.BRLSFORD F'KFINK BowERs ATTORNEY April 4, 1939. w. P. THOMAS ET AL 2,153,213

APPARATUS FOR DETERMINING LIQUID LEVELS Filed Jilly 31, 1935 2 Sheets-Sheet 2 ATTORNEY Patented Apr. 4, 1939 APPARATUS FOR DETERRIINING LIQUID LEVELS Willis P. Thomas, Highland Park, Curtis L. Howse, Detroit, Harry E. Brelsford, Birmingham, and Frank Bowers, Detroit, Mich assignors to Diamond Power Specialty Corporation, Detroit, Mieh., a corporation of Michigan Application July 31, 1935, Serial No. 33,926

6 Claims. (01. 73297) This invention relates to an apparatus for determining liquid levels and has particular reference to an apparatus for determining the level of water in a boiler drum or the like.

One of the primary objects of this invention is to provide an apparatus of the above mentioned character which will function efficiently over a wide range of boiler pressures.

A further object of this invention is to provide an apparatus of the above mentioned character which will include pressure responsive means for indicating the level of water in a boiler drum and which will include means for varying the effective operation of the pressure responsive means in dependence upon the pressure in the boiler with which the apparatus is associated.

Numerous other objects and advantages of this invention will become more apparent as the following description proceeds, particularly when reference is had to the accompanying drawings wherein Fig. l is a side elevational view of an appara tus constructed in accordance with the teachings of this invention;

Fig. 2. is a sectional view taken substantially on the line 2-2 of Fig. 1;

Fig. 3 is an enlarged sectional view taken on line 3-3 through a portion of the structure shown in Fig. 1;

Fig. 4 is a semi-diagrammatic View similar to Fig. 1 showing a slightly modified form-of construction;

Fig. 5 is a view similar to Fig. 4 showing a further embodiment of the inventive idea;

Fig. 6 is a sectional View similar to Fig. 2 showing a modified type of valve for use in the structure shown in Fig. 5;

Fig. 7 is a sectional view through a modified form of valve which may be utilized; and

Fig. 8 is an 'elevational view of the valve member forming a part of the structure shown in Fig. 12.

In Patent No. 1,936,907 issued to Curtis L. Howse under date of November 28, 1933, there is disclosed a construction which comprises generally an expansion chamber, means for placing said chamber in communication with a boiler at any one of a plurality of spaced levels, a restricted outlet for the expansion chamber and a means associated with the expansion chamber for indicating the pressure in the expansion chamber. The structure and operation of the apparatus disclosed in this patent will be briefly outlined as the following description proceeds, since in its broader aspects the present invention constitutes an improvement on the apparatus disclosed in the said patent.

Referring now particularly to the drawings wherein like reference characters designate corresponding parts throughout all views, the numeral l5 designates a liquid chamber such for example, as a boiler drum, while the numeral l6 designates the normal water level in this drum. In accordance with the usual practice, the boiler drum is connected above and below the normal level of the water therein by means of conduits I! to a water column l8. Tapped into the water column, at spaced levels therein, are guage cocks l9, and the outlet from each gauge cock is connected by' means of a conduit to an expansion chamber 2|.

Tapped into the expansion chamber adjacent the upper end thereof is a conduit 22 which communicates with a pressure gauge 23 which may be of any desired construction. As indicated in Fig. 1 of the drawings, this pressure gauge is preferably provided with suitable indicia with which the pointer 24 cooperates to indicate steam, mixture and water. Additionally, the expansion chamber 2| is provided adjacent its lower end with a discharge conduit 25 which in the said Patent No. 1,936,907 was provided with a restricted discharge orifice of fixed construction.

The apparatus as thus far described, is substantially the same as that disclosed in the said patent and operates as follows: In determining the level of the water in the boiler drum, the gauge cocks l9 may be successively opened one at a time. As each gauge cock is opened, fluid will flow from the boiler at the particular level at which the gauge cock communicates with the water column and will be discharged into the chamber 2|. The gauge 23 associated with this chamber will show the pressure Within the chamber and will show higher pressure if water is discharged into the chamber than if steam is discharged into the same. This results from the fact that when water is admitted to the expansion chamber, this water flashes into steam because of the relatively low pressure within this chamber and since the outlet to the chamber is restricted, and the volume afforded by the chamber is limited, there is a momentary building up of pressure in the chamber 2| which is indicated by the gauge 23. This momentary increase in pressure within chamber 21 does not occur when steam is admitted to chamber 2| from the boiler drum with the result that the pressure registered on gauge 23 indicates whether the chamber has been placed in communication with the boiler above or below the level of the water in the same.

The apparatus disclosed in the patent operates most efiiciently at full boiler Operating pressure or near to full pressure in view of the fact that the gauge 23 is necessarily limited as to the pressures to which it may be efiiciently responsive. It is desirable however, to adapt the apparatus to the indicating of liquid levels regardless of the pressure at which the boiler is operated to the end that the apparatus will function eificiently when the boiler is at full boiler pressure, is on bank, or is coming up on the line or down from the line. The present invention obtains this desired result by the provision of means whereby the effective operation of the gauge 23 varied in dependence upon variations of the pressure in the boiler with which the apparatus is associated.

Referring now again to Fig. 1 of the drawings, it will be expedient first to describe the structure of the gauge cocks l9 since these gauge cocks differ somewhat in construction from those disclosed in Patent No. 1,936,907. One of these gauge cocks is shown in section in Fig. 2 of the drawings and by reference to this figure it will be noted that the same comprises a nipple 30 adapted to be threaded into the water column or the boiler whichever is more convenient. This nipple is threadedly secured by a sleeve 3| to a tubular body 32 which is interiorly threaded as at 33 for threaded engagement with the threaded portion 34 of the valve actuating stem 35. This valve actuating stem is provided at its outer end with an actuating lever 36 by which it may be rotated and terminates at its inner end in a recessed portion 31 which is loosely secured to a valve body 38 by set screws 39. The valve body is provided with a conical portion 40 adapted to engage a valve seat 4| and the valve body is also provided with an extension 42 suitably guided within the nipple 30.

The valve 38 controls communication between a bore 45 formed in the nipple 3i) and a chamber 46 formed in the valve body 32 with the result that when valve 38 is opened fluid from the boiler is admitted to chamber 46.

Threaded into the valve body is a nipple 5B and threadedly secured to this nipple is conduit 20 which places the bore 5| formed in the nipple 50 in communication with the chamber 2|. It will be noted that in the form of invention shown in Fig. 2, the bore 5| is restricted so as to provide an orifice between the boiler or water column and the expansion chamber 2|. The gauge cock is of such construction that there is no orifice between the bore 45 and the chamber 46.

As previously mentioned, it is an object of this invention to provide an adjustable orifice in the discharge conduit 25-and to provide means for adjusting this orifice in dependence upon the pressure in the boiler with which the apparatus is associated.

Referring particularly to Fig. 3 wherein the means for accomplishing this result is illustrated, the numeral designates generally the adjustable orifice structure. It comprises a fitting 56 which is secured to the discharge conduit 25, this fitting carrying a partition 60 affording a valve seat 6 l. Adapted for cooperation with this valve seat is a conically shaped valve 62 which is secured by a stem 63 to a headpfifl. This head is suitably secured to a pressure responsive diaphragm 65 located ina suitable diaphragm housing 66. Disposed Within-the diaphragmhousing and arranged to act on the head 64 of the valve stem is a spring 61, this spring acting to urge the valve 62 toward closed position. Communicating with the diaphragm housing is a conduit 68 which is tapped into the boiler or the water column as at 69. To eliminate the use of stufiing boxes, the valve 62 and its actuating mechanism are preferably sylphon packed, there being a collapsible bellows 10 secured to the valve 62 and to the interior of fitting 56 and there being a second collapsible bellows 1| secured to the head 64 and the adjacent portion of the diaphragm housing 66.

Before proceeding with a complete description of the operation of the apparatus as thus far described, it might be noted that the structure disclosed in Fig. 3 functions as follows. The spring 6! acts tohold the valve 62 either closed or substantially closed so that the discharge orifice for pipe 25 is either wholly restricted or substantially restricted. Acting in opposition to the spring 61 is the pressure supplied to the dia phragm housing by virtue of conduit 68 with the result that as the boiler pressure increases the valve 62 is opened and the discharge orifice thus increased in size.

As previously mentioned, in the patented apparatus the operation depended upon the increase of pressure in the expansion chamber incident to the discharge into this chamber of water which flashed into steam. Obviously with the orifice of constant size there would be no control over the discharge from the expansion chamber with the result that should the boiler be under relatively low pressure the discharge from the expansion chamber might be so rapid that a sufficient pressure might not be built up in the same to effect the desired actuation of the pressure gauge. With the present construction however, the size of the orifice is adjusted in. accordance with the pressure within the boiler with the result that at low pressures the orifice will be so restricted that the desired pressure will be built up in the expansion chamber while at high pressures the orifice will be increased in size with the result that too high a pressure will not be built up in the expansion chamber. The operation of the apparatus will of course consist in successively opening the gauge cocks one at a time to place the expansion chamber in communication with the boiler drum at successive levels. If steam is admitted to the expansion chamber the gauge 23 will indicate a lower pressure than if water is admitted to the expansion chamber with the result that the gauge 23 will definitely indicate whether water, steam or a mixture of water and steam is admitted to the expansion chamber.

From the above it will be apparent that the invention provides an apparatus which will operate efliciently down to a certain minimum pressure which of course will be determined by the characteristics of the dial gauge 23 and the radiation characteristics of the piping, valves and expansion chamber. To more fully point out the advantages of the present construction it might be assumed that the pressure gauge is designed to give a full range of pressure of 75#. With a fixed orifice in conduit 25 it would be necessary that the size of this orifice and the sizes of the orifices in the gauge cocks be so adjusted that at normal operating pressure of the boiler sufficient heat energy would be supplied to expansion chamber 2| when water was admitted to cause the pointer 24 to rotate approximately 220 to indicate water. Instead of a pressure range of 75#, a range of 25 to 30# might have been selected for the spring in the pressure gauge, but even with this lower range it would be necessary with a fixed orifice, for the boiler to reach a pressure of between 60 and 70# before sufiicient heat energy would be put into the expansion chamber to take care of radiation and loss of pressure through the fixed orifice and build up a pressure of 30# to give the desired indication.

By adjusting the size of the discharge orifice however, in accordance with the pressure in the boiler, the apparatus may function efliciently from any desired minimum pressure up to any desired working pressure of the boiler. Thus the present invention increases to a substantial de-- gree the range of indication of the apparatus.

In actual operation theremay be cases where it is not desirable or practical to constantly main tain full boiler pressure on the diaphragm 65, and the present invention therefore contemplates the provision of means whereby the diaphragm 65 will be subjected to the boiler pressure only when the apparatus is being operated to determine the level of the water in the boiler drum. An arrangement for accomplishing this result is illustrated in Fig. 4 of the drawings wherein the expansion chamber is indicated by the reference character 2 l this expansion chamber being connected at spaced levels to the boiler drum by conduits 20 and valves l9 It will be understood that the valves l9 may be gauge cocks such as illustrated in Fig. 2 of the drawings or any other type of valve and that further these valves may be tapped directly into the boiler l5 as illustrated or into a suitable water column (not illustrated).

As in the first described construction, the expansion chamber is provided with a discharge conduit 25 which in turn is provided with an adjustable orifice 55" adapted to be actuated by a suitable diaphragm located in the diaphragm housing 66*. The conduit (58 communicates with the diaphragm housing and with the boiler for supplying boiler pressure to the diaphragm as will be apparent.

This modified embodiment of the invention however, contemplates locating in the conduit 58 a valve 15. This valve is normally held closed by a spring or the like (not shown) and for opening this valve there is provided a suitable pressure actuated device 16 which may obviously be a. diaphragm such as is located in the housing 66. The pressure actuated device 16 is connected by a conduit 11 to the conduit 22 which connects the expansion chamber 2| to the pressure gauge 23.

It will be understood that when the apparatus is not being utilized to determine the level of the water in the boiler drum, there will be little or no pressure in chamber 2N and that therefore valve 15 will be closed. Likewise it will be apparent that with little or no pressure on the diaphragm in the housing 66 the discharge orifice for the expansion chamber will either be closed or restricted to a substantial extent.

When however, one of the valves I9 is opened and pressure is built up in expansion chamber 2|, this pressure will act on the pressure device 16 opening valve 15 and thus subjecting the diaphragm 65 to the boiler pressure. Thus with this modified form of construction, the diaphragm 65 will only be subjected to the pressure in the boiler when the apparatus is being utilized for determining the level of the water in the boiler.

In Fig. 5 there is disclosed a modified form of the invention in which indications may be obtained from zero pressure in the boiler up .to full operating pressure. Referring now to this figure,

the expansion chamber 2I is illustrated as connected at spaced levels to the boiler li by conduits 20 and valves l9 As in the first described form of construction there is connected to the expansion chamber a pressure gauge 23 .and a discharge conduit 25 having an adjustable orifice adapted to be actuated in dependence upon the pressure in the boiler by virtue of the conduit 68 The valves l9 may, as illustrated in Fig. 6 of the drawings, be identical with the gauge cocks 19 with the exception that there is tapped into each gauge cook a. conduit 80. Each conduit communicates with the chamber 46 in its respective gauge cock. As previously mentioned, the gauge cocks are so constructed that there is no orifice in the gauge cock between the bore 45 and thus the boiler and the chamber 46' with the result that when the gauge cocks are opened there is freedom of discharge for the contents of the boiler through the gauge cocks and the conduits 8D. The conduits 80 are likewise free from orifices so that any fluid admitted to the same from the gauge cocks will flow freely through these conduits.

The conduits 80 are arranged to discharge into a drain funnel BI and each conduit 8 is provided with a valve 82 adjacent its discharge end. It will of course be understood that the discharge ends of the conduits 80 are so associated with the funnel 8! that the discharge from the conduits may be readily observed.

In certain modern types of boiler installations it is the custom to locate the boiler in a compartment separate from the operators. It therefore is a feature of this embodiment of the invention that the operating and indicating mechanism for the testing apparatus is located in a room or compartment separate from the boiler. Thus,

as illustrated in Fig. 5, the numeral designates I a suitable bulk-head and the conduit '22 passes through this bulk-head as do the conduits 80. Additionally, the stems (s5 of the gauge cocks likewise pass through this bulk-head with the result that the gauge cocks may be operated and the indicators observed in the compartment 86 which is separate from the compartment in which the boiler is located.

In the operation of this embodiment of the invention, it will be apparent that the gauge cocks I 9 may be successively opened one at a time and that at zero or low boiler pressures the corresponding valves 82 in the conduits 80 may be opened one at a time and an observation made as to whether or not water, air or steam is discharged from these conduits into the funnel 8|. As the pressure of the boiler increases to the point where it becomes inadvisable to make these observations, the level of the water in the boiler may be determined by observing the gauge 23, it being of course understood that when the boiler pressure is increased, the valves 82 are closed and the conduits 80 not thereafter utilized unless the boiler pressure drops again to a point where their use is possible.

In the constructions which have been described reference has been made to an adjustable orifice produced by a conically shaped valve. It will be obvious, however, that any type of valve might 'be utilized for the adjustable orifice and for this reason a modified form of valve is illustrated in Figures 7 and 8.

Referring to these figures, the numeral 25 designates the discharge conduit from the expansion chamber, this conduit discharging into a .a closed or substantially closed position such as illustrated in Fig. '7. The valve is however, provided with a stem I56 to which is secured a piston 15'! which is adapted to be acted upon by fiuid pressure supplied to the cylinder I50 by conduit 68 It will of course be apparent that the conduit 68 is connected to the boiler with the result that as the pressure in the boiler increases, the valve will be moved to the right as viewed in Fig. '7, thus increasing the size of the orifice formed by the slot I52 and the adjacent portion of the wall of cylinder I50. It will be obvious that this valve or any other suitable valve might be utilized for the adjustable orifice in the previously described embodiment of the invention.

From the above it will be apparent that the invention provides a pressure gauge so associated with a boiler as to indicate whether water, steam or a mixture of steam and water is discharged from the boiler at a determined level. The invention provides means for varying the effective actuation of the pressure gauge as the pressure in the boiler varies, with the result that the apparatus will function efficiently over a wide range of pressures.

While the invention has been described with some detail, it is to be understood that the description is for the purposes of illustration only and is not definitive of the limits of the inventive idea. The right is reversed to make such changes in the details of construction and arrangement of parts as will fall within the purview of the attached claims.

Whatwe claim as our inventionis:

1. In an apparatus for determining whether or not water is at a predetermined level in a boiler, means for tapping the boiler at the said predetermined level, means providing a restricted zone for receiving the fluid discharged from the boiler at said level, pressure responsive means connected with said restricted zone, means providing a discharge orifice for said restricted zone, and pressure actuated means responsive to the pressure in the boiler for adjusting the size of said discharge orifice.

2. In an apparatus for determining whether or not water is at a predetermined level in a boiler, means for tapping the boiler at the said predetermined level, a chamber providing a restricted zone for receiving the fluid discharged from said boiler at said level, pressure responsive means connected with said' restricted zone, an'outlet conduit for said chamber, a valve controlling the discharge through said outlet conduit, and pressure actuated means responsive to the pressure in the boiler for actuating said valve.

3. In an apparatus for determining whether or not water is at apredetermined level in a boiler, means for tapping the boiler at the said predetermined level, a chamber providing a restricted zone for receiving the fluid discharged from the boiler at said level, pressure responsive means connected with said restricted zone, a valve controlling the discharge of the fluid from said chamber, and pressure actuated means responsive to the pressure in the boiler for actuating said valve in dependence upon'the pressure in the boiler.

4. In an apparatus for determining whether or not water is at a predetermined level in a boiler, means for tapping the boiler at the said predetermined level, means providing a restricted zone for receiving the fluid discharged from the boiler at said level, pressure responsive means connected with said restricted zone, means providing a discharge orifice for said restricted zone, and pressure actuated means responsive to the pressure in the boiler operating to increase the size of said discharge orifice as the pressure in the boiler is increased.

5. In an apparatus for determining whether or not Water is at a predetermined level in a boiler, means for tapping the boiler at the said predetermined level, a chamber providing a restricted zone for receiving the fluid discharged from said boiler at said level, pressure responsive means connected with said restricted zone, a valve controlling the discharge of the fluid from said chamber, a diaphragm connected to said valve for actuating the same, and means for subjecting said diaphragm to the pressure in the boiler.

6. In an apparatus for determining whether or not water is at a predetermined level in a boiler, means for tapping the boiler at the said predetermined level, a chamber providing a restricted zone for receiving the fluid discharged from the boiler at said level, a valve controlling the discharge of the fluid from said chamber, a movable member, means subjecting one side of said member to the pressure in the boiler, means acting on the oposite side. of said member opposing the force exerted on said member by the pressure in the boiler whereby the said member assumes a position dependent upon the pressure in the boiler, a connection between said movable member and said valve for actuating the latter from the former and pressure reponsive means connected with said chamber.

WILLIS P. THOMAS. CURTIS L. HOWSE. HARRY E. BRELSFORD. FRANK BOWERS. 

